Ok, on va essayer de remédier à cela en faisant un lien symbolique 
# ln -s /etc/bumblebee/xorg.conf.nvidia /etc/bumblebee/xorg.conf.nvidia-current
Puis, redémarrage de Bumblebee et test optirun
c’est liée à la même erreur en fait !
Et, non, c’est normal … soit ça fonctionne sans soucis … soit non !
Oui, c’est toujours pour accéder aux deuxième GPU 
Voici la réponse:
[ 7515.711790] [ERROR]Cannot access secondary GPU - error: [XORG] (EE) Failed to load module "nvidia" (module does not exist, 0)
[ 7515.711812] [ERROR]Aborting because fallback start is disabled.Pardon, je vous ai induit en erreur ici …
Il fallait modifier par “Driver=nvidia” !!!
PS : je commence à fatiguer, moi 
ah très bien, je modifie ça tout de suite.
Voici la réponse:
[ 8101.114096] [ERROR]The Bumblebee daemon has not been started yet or the socket path /var/run/bumblebee.socket was incorrect.
[ 8101.114175] [ERROR]Could not connect to bumblebee daemon - is it running?C’est que le service Bumblebee n’est pas démarré ou n’a pas pu !
Vérifier votre modification du fichier /etc/bumblebee/bumblebee.conf
Puis, si correct, essayez de le redémarrer
Yes, je vérifie, j’ai bien mis Driver=nvidia
# Configuration file for Bumblebee. Values should **not** be put between quotes
## Server options. Any change made in this section will need a server restart
# to take effect.
[bumblebeed]
# The secondary Xorg server DISPLAY number
VirtualDisplay=:8
# Should the unused Xorg server be kept running? Set this to true if waiting
# for X to be ready is too long and don't need power management at all.
KeepUnusedXServer=false
# The name of the Bumbleblee server group name (GID name)
ServerGroup=bumblebee
# Card power state at exit. Set to false if the card shoud be ON when Bumblebee
# server exits.
TurnCardOffAtExit=false
# The default behavior of '-f' option on optirun. If set to "true", '-f' will
# be ignored.
NoEcoModeOverride=false
# The Driver used by Bumblebee server. If this value is not set (or empty),
# auto-detection is performed. The available drivers are nvidia and nouveau
# (See also the driver-specific sections below)
Driver=nvidia
# Directory with a dummy config file to pass as a -configdir to secondary X
XorgConfDir=/etc/bumblebee/xorg.conf.d
# Xorg binary to run
XorgBinary=Xorg
## Client options. Will take effect on the next optirun executed.
[optirun]
# Acceleration/ rendering bridge, possible values are auto, virtualgl and
# primus.
Bridge=auto
# The method used for VirtualGL to transport frames between X servers.
# Possible values are proxy, jpeg, rgb, xv and yuv.
VGLTransport=proxy
# List of paths which are searched for the primus libGL.so.1 when using
# the primus bridge
PrimusLibraryPath=/usr/lib/x86_64-linux-gnu/primus:/usr/lib/i386-linux-gnu/primus:/usr/lib/primus:/usr/lib32/primus
# Should the program run under optirun even if Bumblebee server or nvidia card
# is not available?
AllowFallbackToIGC=false
# Driver-specific settings are grouped under [driver-NAME]. The sections are
# parsed if the Driver setting in [bumblebeed] is set to NAME (or if auto-
# detection resolves to NAME).
# PMMethod: method to use for saving power by disabling the nvidia card, valid
# values are: auto - automatically detect which PM method to use
# bbswitch - new in BB 3, recommended if available
# switcheroo - vga_switcheroo method, use at your own risk
# none - disable PM completely
# https://github.com/Bumblebee-Project/Bumblebee/wiki/Comparison-of-PM-methods
## Section with nvidia driver specific options, only parsed if Driver=nvidia
[driver-nvidia]
# Module name to load, defaults to Driver if empty or unset
KernelDriver=nvidia
PMMethod=auto
# colon-separated path to the nvidia libraries
LibraryPath=/usr/lib/x86_64-linux-gnu/nvidia:/usr/lib/i386-linux-gnu/nvidia:/usr/lib/nvidia
# comma-separated path of the directory containing nvidia_drv.so and the
# default Xorg modules path
XorgModulePath=/usr/lib/nvidia/nvidia,/usr/lib/xorg/modules
XorgConfFile=/etc/bumblebee/xorg.conf.nvidia
## Section with nouveau driver specific options, only parsed if Driver=nouveau
[driver-nouveau]
KernelDriver=nouveau
PMMethod=auto
XorgConfFile=/etc/bumblebee/xorg.conf.nouveau
Je vous comprends, moi aussi je commence à fatiguer
C’est vous qui avez modifié cette ligne ?
Si oui, changez-la par :
## Section with nvidia driver specific options, only parsed if Driver=nvidia
[driver-nvidia]
# Module name to load, defaults to Driver if empty or unset
KernelDriver=nvidia-currentNon, ce n’est pas moi. justement j’en parlais tout à l’heure, ça me semblait bisarre.
Je vais essayer avec juste nvidia.
Si je me au KernelDriver=nvidia-current
je met aussi sur la ligne Driver : Driver:nvidia-current
?
Non, il faut qu’elle soit telle que je vous l’ai écrite !
# Configuration file for Bumblebee. Values should **not** be put between quotes
## Server options. Any change made in this section will need a server restart
# to take effect.
[bumblebeed]
# The secondary Xorg server DISPLAY number
VirtualDisplay=:8
# Should the unused Xorg server be kept running? Set this to true if waiting
# for X to be ready is too long and don't need power management at all.
KeepUnusedXServer=false
# The name of the Bumbleblee server group name (GID name)
ServerGroup=bumblebee
# Card power state at exit. Set to false if the card shoud be ON when Bumblebee
# server exits.
TurnCardOffAtExit=false
# The default behavior of '-f' option on optirun. If set to "true", '-f' will
# be ignored.
NoEcoModeOverride=false
# The Driver used by Bumblebee server. If this value is not set (or empty),
# auto-detection is performed. The available drivers are nvidia and nouveau
# (See also the driver-specific sections below)
Driver=nvidia
# Directory with a dummy config file to pass as a -configdir to secondary X
XorgConfDir=/etc/bumblebee/xorg.conf.d
## Client options. Will take effect on the next optirun executed.
[optirun]
# Acceleration/ rendering bridge, possible values are auto, virtualgl and
# primus.
Bridge=auto
# The method used for VirtualGL to transport frames between X servers.
# Possible values are proxy, jpeg, rgb, xv and yuv.
VGLTransport=proxy
# List of paths which are searched for the primus libGL.so.1 when using
# the primus bridge
PrimusLibraryPath=/usr/lib/x86_64-linux-gnu/primus:/usr/lib/i386-linux-gnu/primus:/usr/lib/primus:/usr/lib32/primus
# Should the program run under optirun even if Bumblebee server or nvidia card
# is not available?
AllowFallbackToIGC=false
# Driver-specific settings are grouped under [driver-NAME]. The sections are
# parsed if the Driver setting in [bumblebeed] is set to NAME (or if auto-
# detection resolves to NAME).
# PMMethod: method to use for saving power by disabling the nvidia card, valid
# values are: auto - automatically detect which PM method to use
# bbswitch - new in BB 3, recommended if available
# switcheroo - vga_switcheroo method, use at your own risk
# none - disable PM completely
# none - disable PM completely
# https://github.com/Bumblebee-Project/Bumblebee/wiki/Comparison-of-PM-methods
## Section with nvidia driver specific options, only parsed if Driver=nvidia
[driver-nvidia]
# Module name to load, defaults to Driver if empty or unset
KernelDriver=nvidia-current
PMMethod=auto
# colon-separated path to the nvidia libraries
LibraryPath=/usr/lib/x86_64-linux-gnu/nvidia:/usr/lib/i386-linux-gnu/nvidia:/usr/lib/nvidia
# comma-separated path of the directory containing nvidia_drv.so and the
# default Xorg modules path
XorgModulePath=/usr/lib/nvidia,/usr/lib/xorg/modules
XorgConfFile=/etc/bumblebee/xorg.conf.nvidia
## Section with nouveau driver specific options, only parsed if Driver=nouveau
[driver-nouveau]
KernelDriver=nouveau
PMMethod=auto
XorgConfFile=/etc/bumblebee/xorg.conf.nouveauOui oui, je ne vais pas modifier votre ligne 
Cela fonctionne !!!
Il n’y a plus d’erreur qui s’affiche 
!
et cela lance le programme comme prévu.
Merci mais alors vraiment merci beaucoup pour votre patience, j’ai appris énormément de chose avec ce problème. Notamment comment utiliser Vi et ce n’est pas simple du tout quand on début héhé.
Bon beh, cliquez sur l’icône résolu … et bonne continuation.
Servez-vous d’optirun pour lancer ‘firefox’, ‘vlc’ … ou tout autre application qui demande des ressources graphiques !
Installez ‘nano’
De ce pas
Le fonctionnement correct - relatif au bogue qui nous a posé problème - est corrigé dans la future version de bumblebee, la 3.2.1-11 !
ahahah, comme quoi, à quelque chose près on aurait pu avoir un gros gain de temps
Il n’y avait même pas besoin du lien symbolique que je vous ai fait créer …
ce n’est pas grave
Vous pouvez le supprimer en faisant :
# rm -f /etc/bumblebee/xorg.conf.nvidia-current
Allez, bonne nuit.
Je viens de le supprimer. Merci encore et bonne nuit.